工程机械正流量控制内部资料

2-loopPositiveControlBlockM9-25HydraulicSystemsatBoschRexrothLUDVNegativeControlPositiveControlThrottle-ControlPSTA1+-PSTPSTA1+-A1PST+-OpenCentersystem1.Thepumpflowingoingtothetankwhenthemainspoolisinmiddleposition.2.Withmovingthemainspooltheflowgetsthrottleduntilthepressureraisestotheconsumerlevelandthecylindermoves.3.Thissystemwasoriginallydesignedforconstantpumps,butisusedtodaywithvariabledisplacementpumpstorunonaconstantpowercurve.LoadSensingSystem1.Hereeachaxishasanindividualpressurecompensatorwhichislocatedbeforethemeter-inorifice.2.Thehighestconsumerpressureiscalledtothepumpwhichswivelsouttotherequestedflow.3.Incaseofundersaturationtheconsumerwiththehighestpressurestopsmoving.LoadSensingSystem4.Differentconsumerpressuresarelevelledbythecompensators.5.Theindividualflowtoeachcylinderisinstalledinthemeter-inorificeofthemainspool.6.Whenthedeltapofthecompenatorspringissaturated,thecompensatorclosesandtherearenolossestothetank.FlowSharingSystem1.ThedifferencetoLSsystemsarethecompensators.2.ThedeltapinLUDVisinstalledinthepumpregulatornotinthecompensators.3.Thesignalofthecylinderwiththehighestloadissendtoallcompensators.4.Incaseofundersaturationtheycloseandtheremainingflowwillbeproportionalreducedineachfunction.Noneoftheconsumerstops.RequirementsforControlofExcavator•Goodfinecontrolofconsumers•Simultaneousmovements•Controllability•Lowhydrauliclosses•Efficientuseofpower•Compactdesignofcomponents•Spacesavingandservicefriendlyinstallation•Possibilityofaddingoptions•FastmovementsComparisonofExcavatorControlPrinciplesThreeDifferentSystemsFlowSharingSystems,LUDV•itcanberealiseda1-loopsystemwithaloadindependentcontrol.Itisusedincrawlerexcavatorssmaller20tonandwheeledexcavatorsNegativeControl1.ItisaOpenCentresystemmainlyusedfromJapaneseandKoreancompanies.2.InneutralthepumpalwayssaturatestheNCorifices.3.Whenamainspoolgetsmovesoutofcentre,theneutralclosesandthepressureattheNCorificedrops.Thisswivelsoutthepump.ThreeDifferentSystemsPositivecontrol1.ThisisalsoaOpenCentresystem,basedontheNCsystems.2.ThereisatendencyofJapanesecompaniesmovingtowardsthissystem.3.Thepilotpressurewhichmovesthemainspoolisalsousedtoswiveloutthepump4.Theadvantageisanindependentmanagementofvalveandpump.1-loopSysteminFlowSharingforWheelExcavator1-loopSysteminFlowSharingforCrawlerAdvantagesofLUDVSystemsinExcavators1.Sensitiveandloadindependentcontrolofdifferentconsumers2.Constantfinecontrolatsingleandsimultaneousmovements3.DefinedspeedcontrolforeachconsumerbyindividualflowadjustmentTheoperatordoesnothavetothinkaboutchangingleverstrokes,becausetheRexrothLUDV-systeminstantly,silentlyandautomaticallysendjusttherightamountofoiltotheactuators,atjusttherightpressuretoaccommodatethechange.Thefrontendequipmentworksnaturallywiththeoptimumcombinationofspeedandpower.PriorityforoptiononrequestpossibleAdvantagesofLUDVSystemsinExcavators4.FlexibilityforOptions•easytoadoptoneormoreoptionalconsumersasallfunctionsareparallel•PriorityforOptiononRequest5.1-loopSystempossible•onlyonevariabledisplacementpumpneededforallfunctionsLUDVControlBlockM7-ApplicationsNewRexroth1-LoopFlowSharingBlockNew1loopLUDVBlockM7-400•6sectionmonoblock•Spoolsontwolevelsforaverycompactdesign•Sectionflowupto420lpmduetospooldia.32mmforBoomandArm•Mainlyfocusedonel.-hydraulicremotecontrol•Easytoattachoptions,alsowithpriority(MFV)•Newarm-andboomregenerationsystemforfasteractuatorspeedwithoutcavitation•AntidriftvalvesonBoompistonsideandArmrodside•BoomfloatingpossibleComparisonofDesignComparison:LUDV:Systemwithhighflexibilityforoptions,individualflowadjustmentforconsumer,loadindependent,1-loopSystempossibleNegativeControl:In2-loopagoodtechnicalandprovensystemPositiveControl:•ImproveddevelopmentbasedonNegativeControl,•PumpisnolongercontrolledbybackpressurefromNCorifice,•Pumpisswiveledoutbypressuresensorsinpilotlinesandelectronic,•Withthis,independentandconsumeradjustedflowcontrolledbythepump.•Energysavingsasnolossesinneutral,andnocontrollossesatswivelingoutthepumpBoschRexrothControlsforExcavatorpIpIMCTH6(pilotcontrolunits)OpenCenterGFB+A10FD(slewdrive)A8VO(travelandimplementhydraulics)MX-25GFT+A10FD(traveldrive)PositiveControlA1pIMCpilotpressureDREpilotpressureNewRexroth2-LoopPositiveControl6M9-25NewRexroth2-LoopPositiveControl7M9-25NewGenerationHydraulicvalvefor20to40tonCrawlerExcavatorSystem1.Techn.keydata:•pumpflowQ=2x210...300Ltr./min(2loopsystem),•Pressurep=400/420bar•hydr.orelectr.hydr.Operated2.Increasedmachineproductivityandhighercontrollabilitythroughindependentvalve/pumpmanagement(pumpiscontrolledbylogicinsteadofvalvesignal)3.BaseforfutureElectroHydraulic(EH)Controls(electr.Logicreplacestodayshydrauliclogic)4.Stillsimple,robust,dynamic,flexibleandreadyforthefuture(EH)(advantagesofallcurrentsystemsinonesystem)DescriptionTopoint1:Maxflow300l/mintocoveramachinerangeuptoaround38ton.Topoint2:InNCthepumpiscontrolledbyvalvesignalTopoint3:Eventuallyin2or3steps1.totalhydraulicmanagement2.hydraulicpiloting-Pressuresensorsforpumpmanagement3.hydraulicpiloting-Pressuresensorsforallpilotsignals4.totalel/